Snowpiercer, the Great Ark Train, has kept the last remnants of humanity alive for almost seven years. A rigid class system maintains order, with First Class holding power over workers, while a condemned Prison Class struggles to survive in the Tail. Now, a grisly murder ...
Layton uses his new position as train detective to investigate the murder while gathering intel for the revolution on the side. Meanwhile, Melanie faces a resource crisis, with potentially drastic consequences for the entire train.
Layton descends into Snowpiercer's black market with Till, searching for both the killer and a valuable commodity for his revolution. Melanie stages a prize fight to distract the passengers from mounting class tension.
A twist in the murder investigation brings Layton face to face with the murderer, and dangerously close to Melanie's secret.
Tension between Third Class and First Class comes to a head at the trial of the Snowpiercer killer.
Hiding out with help from his allies, Layton lays track for revolution. Meanwhile, an engineering emergency threatens every soul on Snowpiercer, and Melanie is the only one who can save them.
Melanie intensifies her search for Layton as he plots to weaponize her secret.
Revolution has finally come, and Layton leads the lower classes forward in armed rebellion. Melanie's house of cards collapses and she's in danger of becoming the first casualty in the battle for control of Snowpiercer.
The rebel forces are on their heels when a dangerous foe joins them. A plan is hatched to take the train, but it may destroy them all.
In the revolution's aftermath, Layton struggles to govern the shell-shocked survivors. Melanie finally makes peace with her demons, only to realize the biggest threat to their survival is right over her shoulder.